Water-repellent composition and method of making the same



Patented Nov. 16,1925.-

UNITED STATES j E 1,607,405 ATENT- OFFICE, I 1

3mm s. LUKENS. or PHILADELPH-IEA, PENNSYLVANIA, assrqnon r somnmmn CORPORATION, OF PHILAIDELPHIA, PENNSYLVANIA, a CORPORATION or DELA- WARE.

WATER-BEPELLENT COMPOSITION AN D METHOD OF MAKING THE SAME.

Ho Drawing. Application filed June 15,

Mdy invention relates to the making of pro ucts from plastic compositions, with or without the use of aggregates, and particularly to the plastic compositions employed 6 in connection with the buildingtrades.

Thisapplication is a continuation in-part of m pending application, Serial No. '48,- 140, led August 4, 1925, for composition of matter and method of making the same.

The object of my invention is to improve the water-repellent or watcr-resistant-properties of such products; and the invention is particularly applicable to factory-shaped 'articles, although it may be used for making floors or other parts which are shaed in place. While particularly adapted or the binding of aggregates, it may be employed in composition articles, such as those made of gypsum, where the pulverulent' material acts as its own binder with or without the addi- .tion of aggregates.

In former attempts to improve the Waterrepellent characteristics oi such compositions i by the introduction of water-repellent substances in the mixture, two general methods have been proposed.

"Ilhe first method was to introduce waterrepellent substances in a state of subdivision into the dry materials before adding water or the necessary liquid, to cause the cementing agent to react and bind the material together. Examples of such a method are those proposing to add water-insoluble soaps or atomized parafiin or waxes or combinations of'the same to Portlandcement or to a portion of the aggregate used in' making I the roduct. In such cases, the distribution of t e water-repellent material is not uniform, but is segregated and will be irregular 40 and dependent upon the efiiciency of the mixer.

A second method consisted of mixing an emulsion of the water-repellent substances with the material forming the composition,

- the water-repellent substances constitutiililg the internal or dispersed phase of the em .sion and water being usually employed for the external hase of-the emulsion. As one example of t is second method, it has been proposed to emulsify water-resistant materials, such as waxes, by means of soluble soaps, such as sodium palmitate or sodium stearater or sodium ol'eate, and to add such -of 30% or more of stren 19' 2e. Serial 1%. 116,069.

an emulsion to Portland cement. In such cases, the calcium hydroxide content of the Portland cement converts these soluble soaps into insoluble lime soa-ps, giving sodium hydroxide as a byproduct. This'sodium hydroxide will absorb carbon dioxide from the air, and thereby be converted into sodium carbonate and water. The; sodium carbonate is of greater volume than the corresponding amount of sodium hydroxide and conse-- to add insoluble soaps, such as a uminum palmitate and calcium stearate, suspendedin a solution of water and ammonia. Tests on products thus made, however, showed aloss over that' shown by the'same materialw en the soapsowereomitted; moreover, such substances are unstable and tend to break down in time by oxidation-both throu h the action of atmospheric agencies and l iy interaction with the constituents of the cement, or by a combination of both causes of disintegration.

After long experimentation upon the second general method above referred to, I have found wh former proposed methods were unsuccess 1 and have discovered mthods by which the difiiculties may be overcome and permanent' water-repellent properties. imparted by observing the following conditions. a

1. The water-repellent-substance should be v stable and unaltered by atmospheric 9. ncies of all kindsor by the constituents ot t he cement.

2. The precipitation, cracking or fioccu'lation of the emulsion,of the water-repellent substance should be irreversible and should yield no byproducts that are altered by atmospheric agencies," or are soluble in or softened by water, or that react unfavorably with the constituents of the cenient.

3. The precipitation, cracking or flocculation'o'f' the emulsion or suspension should be conducted in place, i; e., should be brought about at the time of mixing the cement, mortar, or plastic mass just preceding its pouring or other means of application.

, As an example of water-repellent materials conforming 'to the first condition, I will mention the petroleum hydrocarbons of the paraflin series. I do not, however, desire to limit myself to the use of such materials, but may use other materials which remain stable. and. unaltered under the conditions. of use, and are capable of being brought into the form of an emulsion or colloidal suspension such as certain natural waxes, cellulose nitrate, gilsonite, pitches either natural 'or artific'iahasphalt, etc.

As regards the second condition, I would point out that, ifthe cracking, precipitat mg or fiocculating material remains as a constituent of the composition, the reforming of an emulsion or suspension is pre vented, if the substance be subsequently subjected to the action of .water or moisture.

Hence, it is desirable to use some normal constituent of the cement or binder as a cracking agent. -Where thisis not possible, I prefer to add tothe mixture either while dry, or after wetting with my type of emul si'on, a suitable cracking agent which will act to crack or flocculatethe emulsion and yet will yield no byproducts of an objectionable character, such as are formed in the use of soaps of fatty acids in connection with Portland cement, as above referred to.

I do not intend, however, to limit myself to any particular cracking or .fioc'culating agent, so long as the agents used'will form no deleterious byproduct nor introduce materials which tend to weaken the composrtion orcontribute to water absorption or.

disintegration by the action of water.

In carrying out my invention in connection with a material or binder of a general Sorel cement type with or without aggre gate, I introduce into the mixture, for example, an appropriate amount of an emulsion. containing a water-repellent agent, such as an emulsion of oil and water. Some cheap petroleums contain natural emulsifying agents (such as certain sulphomc acids or their derivatives), and these may be mixed up directly with the water or an oil ,may be made into an emulsion with a solid, such as talc, as for example, in a grinding mill; or the water-repellent'matein water rial, such as oil, may be -dispersed by means of aluminum hydroxide; or the water-repellent material, such as oil, may be dispersed in a liquid suspension wholly by mechanical agencies, as by asuitable colloid mill. In this case,-the magnesium chloride of the Sorel cement mixture will act to.

crack the emulsion infplace /without the formation of' any deleterious byproduct.

For example, I have prepared a dry mix ture of:

I then prepared anemulsion of oil by agitating with water an oil containing naturalemulsifying agents. Such oils are well 'known' in the trade and are common in petroleum fractions from certain districts. The oil is usually in the ratio of about one part of oil to nine parts of water, although this ratio may 'be widely varied. This emulsion was then added to the/dry mixture above described to anamount suflicient to form a paste or mortar and the mixing con-' tinued until the magnesium chloride passed intp solution. As the magnesium chloride dissolved, the oil particles dispersed through the liquid constituent tended to separate' and eifectually wet or coat the solid particles. These oil particles had little or no efiect in decreasing the Sorel reaction of the magnesium chloride' with the magnesium oxide. This is shown by the fact thatthe' addition of the emulsion did not material] affect the strength of the resultant materia The water formed in. cracking evaporates.

Products thus produced lose but 10% to 20% of their tensile strength on exposure to water, while when ordinar Sorel cement is used, the decrease in stren h is much greater and more rapid.

It will be noted that in the above example the cracking agent formed a part of the binder, but I may add to the mixture either while dry, or after wetting with my type of emulsion a cracking agent such as an I well known electrolyte, in cases where the incler is of such a nature that this is needed in order to eifectuate'the cracking of the waterrepellent emulsion. V

I am aware that the alkaline earth salts of the sulphonic acids are in general soluble,

than a soluble sulphonate of an alkaline earth is produced and that this compound is substantially insoluble in,water.

or this -In the case of Portland cement, one preferabl-procedure is as follows: If from1% to 3% of a suitable water-repellent material,

such as parafiin .wax, be brought into a highly disper sed condition in water by means of treatmentsin a colloid mill, or dispersed through the medium of a colloid, such as zinc hydroxideprepared by dialysis. and

such an emuls'ii )n' be added toa Portland cement mlxture' n place ofpart or all of the water normally used for making such a mixture, the soluble lime'salts cement bring about a cracking or flocculation of the emulsion or suspension, thereby precipitating the water-repellent materials on the solids. The emulsion contains no deleterious materials to weaken the article. .In

- the precipitation is rendered irreversible by the continued presence of the flocculating or cracking agent.

The process may also be applied to plastic compositions, such as psum products. When common plaster of aris articles are made they take up water, and the gypsum is hydrated. Such. products may be made more resistant to the action of water if, instead of mixing water with theplaster or the plaster mixed with an aggregate, a suitable emulsion be substituted for part or all of the water. In this case, for example, I.-may emulsify a water-repellent material which complies with my requirements, by purely mechanical means in conjunction with the use of a solid water-insoluble emulsifying agent. This may becarried out by rinding the water-repellent agent with the so id, such as talc, tion apparatus, asuitable amount of such an emulsion is 'mixed with the gypsum, sufiicient calcium sulphate dissolves to provide an electrolyte of appropriate concentration to crack the emulsion and thereby cause the water-repellent agent to separate throughout the mass. No deleterious compounds are produced, and a product is thus formed which is far more resistant to the action of water than are ordinary gypsum products.

The water-repellent material used in my emulsion orsuspension may be of organic, inorganic or mixed type, so long as the same complies with my requirements.

I prefer to crack the emulsion without chemical change of the water-resistant materials. With some emulsions this is not possible, chemical change it is essential that all of the non-volatile portions of the reaction products, i. 'e., those which do not evaporateare water-repellent and stable;

I may employ water-resistant materials, such as cellulose nitrate or cellulose'nitrate in conjunction with suitable solvents. If a solvent is used, the nitrate solution may be dispersed by means of appropriate emulsifying agents such as talc. Natural and artificial -waxs and bitumens Wlll all yield favorable results under appropriate condi- In all cases, 1n order obtain my suspension of water'- tions. improved results, the

of the Portland and with water in a suitable vtriturasuch as a colloid mill.' When and in such cases where there isreplellent material should not contain mateme which materially weakens the article I and must be cracked in place; Fi1rthermore, there'must he no deleterious-byproducts set 7 theuse of special fiocculating means as well as the well known action of an electrolyte, but I do not intend to include thereby the mere drying of an emulsion or suspension in place in the mixture.

The' materials above set forth act as waterrepellent agents in the final article, which agents are stable under the conditions of use, that is, they do not oxidize or disintegrate as do the insoluble soaps when so used. a I consider myself the first to add to a plastic composition an emulsion or suspension of a finely divided stable water-repellent agent free from agents which materi ally weaken the product, and then precipi- .tate the wa'ter repellent agent in an irreversiblc'form, while at the same time avoiding any deleterious byproducts as the result of this action.

Articles made from'plastic compositions -in accordance with my. invention are not only highly water-resistant, but have the strength generally required in building materials. Such articles are of good structural strength and high commercial value.

y intend to cover a finely divided suspension of the water-repellent material which is preferably in theform of a colloidal suspension, whether liquid or pasty.

By the term Sorel-plaster-cement type in certain claims I intend to include materials such as binders of the general Sorel type, gypsum products, and lime cements, but to exclude Portland cement.

I claim:

1. In the .manufacture of compositions, the steps consisting of forming a composition containing a binding or cementing ingredient and also containing .an emulsion of a water-resistant stablematerial, cracking the water-resistant ingredient by means of a cracking'agent, repellent article in which all of the nonvolatile products of cracking are water-resistantand stable. A

2. In the manufacture of compositions, the steps consisting of mixing an aggregate with binding material, incorporating in the mixture an emulsion containing a water-resist-ant stable constituent, and cracking the emulsion in the mixture by means of a the term emulsion .in my claims, I

7 By the terms crack- 1 g-:or-flocculating, I intend to include and producing a watercracking agent, all of the non-volatile prodnets of cracking being water-resistant and stable. i

3. In the manufacture of compositions, the steps consistin of forming a compositioir containing a inding ingredient of the Sorel-plaster-cement type. and also containing an emulsion of a water-resistant stable constituent, cracking the emulsion of the water-resistant constituent in the mixture bymeans of a cracking agent, and producing cracked products allof the non-volatile constituents of which are water-resistant and stable.

4. In the manufacture of compositions, the steps consisting of forming a composition containing a cementing ingredient which contains a cracking agent and also contains an emulsion of a water-resistant stable constituent, and cracking the emulsion of the water-resistant, constituent by the cracking agent of the binder while producing products all of the non-volatile portions of which are water-resistant and stable.

5. In the manufacture of gyipsum compositions, the steps consisting o forming a gypsum composition containing an emulsion of a water-resistant stable material,

cracking the water-resistant ingredient by means of a cracking agent, and producing a water repellent gypsum article in which all the non-volatile products of cracking are water resistant and stable. I a

- 6:-:As-a--neW'a1ticle-"ofnnanufaeture, a composition of the strength usually required in building material, containing cementing materials and stable water resistant materials, the whole having the characteristics resulting from cracking in the mixture an emulsion, all of the non-volatile portions of which are water resistant and stable.

7. As a new article of manufacture, a composition of the strength usually required in building material, containing a gypsum binder and stable water resistant materials, the whole having the character istics resulting from cracking in the mixture an emulsion, all of the non-volatile;

portions of which are water resistant and stable.

. In testimony whereof I have hereunto set myv hand.

, HIRAM S. LUKENS. 

